Dose reduction in CT examination of children by an attenuation-based on-line modulation of tube current (CARE Dose)

Abstract

In a controlled patient study we investigated the potential of attenuation-based on-line modulation of the tube current to reduce milliampere values (mAs) in CT examinations of children without loss of image quality. mAs can be reduced for non-circular patient cross sections without an increase in noise if tube current is reduced at those angular positions where the patient diameter and, consequently, attenuation are small. We investigated a technical approach with an attenuation-based on-line control for the tube current realised as a workinprogress implementation. The CT projection data are analysed in real time to determine optimal mAs values for each projection angle. We evaluated mAs reduction for 100 spiral CT examinations with attenuation-based on-line modulation of the tube current in a group of children. Two radiologists evaluated image quality by visual interpretation in consensus. We compared the mAs values read from the CT scanner with preset mAs of a standard protocol. Four different scan regions were examined in spiral technique (neck, thorax, abdomen, thorax and abdomen). We found the mAs product to be reduced typically by 10-60% depending on patient geometry and anatomical regions. The mean reduction was 22.3% (neck 20%, thorax 23%, abdomen 23%, thorax and abdomen 22%). In general, no deterioration of image quality was observed. There was no correlation between the age and the mean mAs reduction in the different anatomical regions. By classifying the children respectively to their weight, there is a positive trend between increasing weight and mAs reduction. We conclude that mAs in spiral CT examinations of children can be reduced substantially by attenuation-based on-line modulation of the tube current without deterioration of image quality. Attenuation-based on-line modulation of tube current is efficient and practical for reducing dose exposure to children.

Accuracy of MSCT Coronary Angiography With 64-Slice Technology: First Experience

“…In addition, the implemented anatomy based dose regulation software significantly reduces effective radiation doses. 18 Finally, MSCT and ICA were not performed simultaneously, but the median delay between the two test was small with regard to the natural progression of CAD. 19 In conclusion, our initial results suggest that 64-slice CT allows a non-invasive assessment of haemodynamically significant CAD with a high diagnostic accuracy.…”

The effective dose result of18F-FDG PET-CT paediatric patients

“…Higher tube current will give more radiation dose to patients [4,6]. Thus, adjustment of tube current based on patient size will reduce the radiation dose to patients especially in paediatric patients [24,25]. Furthermore, other CT imaging parameters such as tube voltage, pitch, time per bed and rotation can be adjusted manually to obtain good images [22] rather than rely on AEC function only.…”

Therapy Response Evaluation of Malignant Lymphoma in a Multicenter Study: Comparison of Manual and Semiautomatic Measurements in CT

“…The scan delay was adapted to the anatomic regions (cervico-thoracic 45 s and abdominal 85 s). Images were obtained at 120 kV with a 32 × 0.6 mm² collimation, using a special dosemodulation template for radiation exposure reduction (CARE dose ® ) [21]. All CT data sets were reconstructed at a slice thickness of 1.5 mm with a reconstruction increment of 0.6 mm, which was revealed in a recent study as the optimal slice thickness for segmentation [15].…”